JPH0744955B2 - Angioplasty dilatation balloon - Google Patents

Abstract

The angioplasty light guide catheter has a dilatation balloon (1) which is to be introduced into the vessel to be treated. The inside of the balloon is connected via a shaft to a suction and forcing pump and can therefore be regulated precisely in diameter. Light guides (6) extend over the entire length of the shaft and are coupled to a laser device via a connection piece at the proximal end of the catheter. At the distal end the light guides are embedded in the wall of the dilatation balloon (1). For stenosis ablation using laser light energy, the outlet points of the light guides can be moved radially outwards and inwards by changing the pressure in the dilatation balloon. The distance of the outlet points (6a) from the centre line of the balloon is thus a function of the pressure of the balloon fluid. This distance can thus be altered and controlled in a simple manner. <IMAGE>

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an angioplasty light guiding catheter as defined in the preamble of the independent claim.

[0002]

The use of laser beams to treat stenosis has been proposed more than 25 years ago. This method
In addition to the well-known balloon dilatation method, it enables treatment without surgical operation, and it was extremely promising from the time of its introduction, but laser light was used to open stenotic blood vessels. There is little progress beyond the experimental stage.

[0003]

The main reason for this is that no suitable catheter was available to accurately position the light guide within the blood vessel. This is also because no means has been developed for eliminating the risk of damaging the blood vessel wall.

Angioplasty light guide catheters in which laser light is bundled by a lens are known. Also, publication H
erz + Gefass 5 (1985) page 185, known from the article in FIG. 5, where three concentrically arranged laser light guides can be held stable against a wall in a blood vessel by means of a balloon. . Even with this catheter, it is impossible to perfectly position and control the laser light, and there is a high possibility that the blood vessel will be damaged. Here again, a catheter with a stable laser light guide against the wall has the disadvantage that severe obstructions cannot be treated sufficiently. For such severe obstructions, a catheter with a centrally located light guide is more suitable, as is known from the publication November 1986 JACC Volume 8, (5), 1989-95 (FIG. 1). ing.

The object of the present invention is to control the laser light safely and easily and to adapt it to the general type of stenosis of different degrees without the risk of damaging the vessel wall. Is to provide a catheter.

[0006]

The above object of the present invention is to provide a catheter according to claim 1, that is, a dilatation balloon introduced into a blood vessel to be percutaneously treated and a region where the laser light emitting end is a dilatation balloon. An optical angioplasty light guide catheter that uses laser light energy to remove a stenotic site, wherein the light guide comprises: At least in the region of the dilatation balloon, it has a diameter that is not substantially larger than the wall thickness of the dilatation balloon and is connected to the wall, in particular its tip is radially outward and inward due to changes in pressure within the dilatation balloon. This is achieved by an angioplasty light guide catheter characterized in that it is embedded in said wall so that it can be moved towards it. In a catheter according to the present invention, the distance from the centerline of the balloon to the exit point of the light guide is a function of balloon fluid pressure. This pressure can be adjusted and controlled by the physician in an accurate and simple manner. In the case of a dilatation balloon, which has a correspondingly small diameter at low pressure, the laser light is concentrated in the center of the blood vessel and is therefore suitable for the treatment of severe stenosis. At higher pressures, the exit point is correspondingly closer to the inner wall of the blood vessel, so that the outer region of the stenosis can also be removed. Further advantageous features will be apparent from the dependent claims and the following description.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the present invention will be described in more detail below with reference to the drawings.

FIG. 1 shows a blood vessel 8 having a stenosis site 7.
And a catheter with a dilatation balloon 1 and a catheter shaft 2 percutaneously inserted into a blood vessel is shown in diagrammatic form. The catheter is inserted into the blood vessel using the guide wire 4. The guide wire 4 can extend through the shaft 2 and the dilatation balloon 1 and out of the tip opening 18. As shown in FIG. 5, the shaft 2 is divided by a wall 10 into a lumen 11 for the guide wire 4 and a lumen 12 for pressurized fluid. According to FIG. 4, the lumen 12 has an opening 9
Is connected to the inside 13 of the balloon via the and the suction and pressure pump 16 at the proximal end. The pump 16 allows the pressure inside the balloon 13 to be accurately adjusted in the dilatation balloon 1 and thus the diameter of the balloon to be adjusted, and when the catheter is introduced, the dilatation balloon 1 is deflated in a known manner. In the deployed state, the dilatation balloon 1 has a cylindrical profile between the two tapered ends, as is apparent from FIG.

According to FIG. 2, the wall 5 of the dilatation balloon 1 is
It has an inner layer 5a and an outer layer 5b. The inner layer 5a is preferably made of relatively soft plastic, while the outer layer 5b is preferably made of silicone rubber. Unlike known dilatation balloons, the wall 5 of the dilatation balloon 1 is elastically extensible within certain limits. Light guide fiber or bundle 6
Contacts the inner layer 5a and is covered by the outer layer 5b. These light guides 6 are evenly distributed along the outer circumference of the wall 5 and extend parallel to the longitudinal direction of the catheter 6.
When the balloon 1 is expanded, the outlet 6a of the light guide 6 is
It lies in a circle and lies in the plane intersecting the dilatation balloon at approximately the transition between its cylindrical region 1a and its distal tapered end 1b. The light guide 6 also extends over the axis 2 over its entire length and is coupled to the laser device 15 via a connecting piece 14. The laser device 15 is preferably a pulsating xenon chloride excimer laser. The light emitted from the laser device 15 reaches the exit point 6 a of the light guide 6 via the connecting piece 14 and the shaft 2.

The light guide 6 has a diameter of 0.1 mm, for example, and is extremely flexible. Therefore, the expansion balloon 1
Can be contracted even with the light guide 6 inserted. The radial distance of the light guide 6 from the centerline of the dilatation balloon 1 increases as the fluid pressure present in the balloon increases. Therefore, the distance of the outlet 6a from the centerline of the dilatation balloon 1 is a function of the pressure adjustable by the pump 16. Since the wall 5 is elastically stretchable, it is possible to arrange the outlets 6a in circles of different radii by adjusting the pressure. Therefore, the exit 6a
The laser beam emitted from the laser irradiates the stenosis site 7 at a distance away from the inside of the container or a short distance. If the pressure in the dilatation balloon is relatively low, a correspondingly intense laser beam is directed near the stenosis. On the contrary, when the pressure is higher, the outer region of the narrowed portion 7 is removed by the less dense laser light.

As shown in FIG. 3, the dilatation balloon 1 is positioned in front of the stenosis site 7 and removes the stenosis site 7 using laser light. The position of the dilatation catheter 1 can be observed using the marker strip 17. In addition to utilizing laser light energy to remove strictures, it is also possible to use conventional dilatation balloons with the catheter of the present invention. In this way, the stenosis 7
Can be expanded by the dilatation balloon 1 before and after treatment with laser light energy without replacing the catheter.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a stenotic vessel with a dilatation balloon inserted.

FIG. 2 is a cross-sectional view of a dilatation balloon.

FIG. 3 is a vertical cross-sectional view of the distal end of the dilatation balloon in the stenotic blood vessel portion shown in the schematic view.

FIG. 4 is a vertical cross-sectional view of the posterior region of the dilatation balloon.

FIG. 5 is a sectional view of a catheter shaft according to the present invention.

[Explanation of symbols]

 1 dilatation balloon 2 catheter axis 4 guide wire 5 dilatation balloon wall 6 light guide 7 stenosis site 8 blood vessel 11 lumen 12 lumen 13 balloon interior 14 connection piece 15 laser device 16 pump 17 marker strip

Claims (8)

[Claims] 1. A dilatation balloon to be introduced percutaneously into a blood vessel to be treated and a laser light emitting end located in the region of the dilatation balloon, and some to introduce laser light at the proximal end of the catheter shaft. A light guide catheter for removing stenosis using laser light energy, the light guide being substantially greater than the wall thickness of the dilatation balloon, at least in the region of the dilatation balloon. A blood vessel having a non-diameter and being connected to a wall, in particular the tip of which is embedded in said wall such that it can move radially outwards and inwards due to changes in pressure in the dilatation balloon. Forming light guide catheter. 2. The catheter of claim 1, wherein the light guide has a diameter of less than about 0.5 mm and is flexible. 3. The catheter of claim 1, wherein the light guide is embedded in the wall of the dilatation balloon. 4. The catheter of claim 1, wherein the wall has an inner layer to which the outer layer is applied and the light guide is embedded within the outer layer. 5. The catheter according to claim 4, wherein the outer layer is made of silicone rubber. 6. The catheter of claim 1 wherein the wall of the dilatation balloon is made of a relatively soft and flexible plastic material. 7. A catheter according to claim 1, wherein substantially three or more, preferably 20 or more light guides are provided. 8. A catheter according to claim 1, which is connected to a pulsating xenon chloride excimer laser.